BMW DTC P0843 – Transmission Fluid Pressure Sensor/Switch ‘A’ Circuit High
DTC P0843 meaning on BMW
The Diagnostic Trouble Code (DTC) P0843 for BMW refers to an issue with the Transmission Fluid Pressure Sensor/Switch ‘A’ Circuit registering a high voltage signal. This code is typically triggered when the powertrain control module (PCM) detects that the signal from the transmission fluid pressure sensor/switch ‘A’ is outside the expected range.
BMW DTC P0843 symptoms
Symptoms associated with DTC P0843 on a BMW may include harsh shifting, transmission slippage, delayed engagement when shifting gears, and in some cases, the transmission may go into a fail-safe or limp mode. Additionally, the Check Engine Light (CEL) may illuminate on the dashboard.
BMW DTC P0843 causes
The common causes of DTC P0843 on a BMW include a faulty transmission fluid pressure sensor/switch ‘A’, damaged wiring or connectors in the sensor circuit, low transmission fluid level, dirty or contaminated transmission fluid, or a malfunctioning PCM.
BMW DTC P0843 seriousness
Ignoring DTC P0843 on a BMW can lead to further damage to the transmission system, potentially resulting in costly repairs. It is important to address this issue promptly to prevent any long-term damage to the transmission components.
How to diagnose DTC P0843 on BMW
To diagnose DTC P0843 on a BMW, a mechanic would typically start by using a diagnostic scanner to retrieve the fault code and then perform a visual inspection of the transmission fluid pressure sensor/switch ‘A’ and its wiring harness. They may also conduct a test drive to observe the transmission’s behavior and perform further electrical tests to pinpoint the exact cause of the issue.
How to fix DTC P0843 on BMW
Fixing DTC P0843 on a BMW may involve replacing the faulty transmission fluid pressure sensor/switch ‘A’, repairing or replacing damaged wiring or connectors, ensuring the transmission fluid level is correct and clean, and resetting the PCM to clear the fault code. It is recommended to follow the manufacturer’s repair procedures or seek assistance from a qualified mechanic.
How to erase DTC P0843 on BMW
To erase DTC P0843 on a BMW, you can use a diagnostic scanner to clear the fault code from the PCM’s memory. Once the issue has been addressed and fixed, clearing the code will reset the Check Engine Light and ensure that the system is no longer registering the fault.
Recommended tools & DTC Scanners for BMW
Best Diagnostic App for modern BMWs: BimmerLink
Recommended Bluetooth adapter for Bimmerlink: OBDLink CX
Cable adapter for Bimmerlink: Enet Cable USB Type C
For older BMWs we recommend: Autel AutoLink AL319 (2024 version)
Easy-to-use Multimeter for reliable diagnostics: AstroAI Auto-ranging Multimeter
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